Because the M-DCT shift knob display uses LEDs and also are “monitored, read back, and compared” there might not be interest in attempting to use a modified knob. The knob change could cause faults and codes from the M-DCT electronics. Read the technical description below.
The selector lever is like a game controller (with processor) networked to the transmission computer.
Selector Lever Indicator and Function
The shift pattern, driving program, gear selection indicator on the selector lever are all similar to that of the E6x M5/M6 with SMG. The main difference is that the selector lever
on the gear selector switch in the E9x M3 no longer snaps into the "N" and "R" positions, instead it only snaps into "R".
The M GWS selector lever is self centering as it returns back to its normal starting position on its own, after the driver selects the desired gear. Reverse gear is an exception; because once the shifter lever is moved left and into the "R" position the gear must be manually unselected by the driver. The shift pattern, driving program, gear selection indicator on the selector lever are all displayed in red, depending on the position of the selector lever and driving program selected.
The indicator displays the currently selected driving program and the gear selection options. The indicator consists of the locating light that indicates the shift pattern and the function indicator lamp. These are two different red position LEDs that show the currently selected driving program and the gear selection options.
The function indicator lamp in the M GWS is controlled by the M DCT electronics. The function indicator lamp is monitored, read back and compared with the required indicator for plausibility. In addition to the PT-CAN connection; there is a LIN-bus connection built in to the M GWS for redundant communication with the M DCT electronics.